Packing Coil

ABSTRACT

An occlusion device formed of a microcoil having a three-dimensional relaxed state employing open looped portions interposed between closed loop portions. Planes defined by sequentially formed open looped and closed loop portions are neither coincident nor parallel to one another.

RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 13/470,127 filed May 11, 2012 entitled PackingCoil, which claims benefit of and priority to U.S. ProvisionalApplication Ser. No. 61/485,059 filed May 11, 2011 entitled PackingCoil, and to U.S. Provisional Application Ser. No. 61/536,478 filed Sep.19, 2011 entitled Packing Coil, all of which are hereby incorporatedherein by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to devices for the occlusion of bodycavities, such as the embolization of vascular aneurysms and the like,and methods for making and using such devices.

BACKGROUND OF THE INVENTION

The occlusion of body cavities, blood vessels, and other lumina byembolization is desired in a number of clinical situations. For example,the occlusion of fallopian tubes for the purposes of sterilization, andthe occlusive repair of cardiac defects, such as a patent foramen ovale,patent ductus arteriosis, and left atrial appendage, and atrial septaldefects. The function of an occlusion device in such situations is tosubstantially block or inhibit the flow of bodily fluids into or throughthe cavity, lumen, vessel, space, or defect for the therapeutic benefitof the patient.

The embolization of blood vessels is also desired in a number ofclinical situations. For example, vascular embolization has been used tocontrol vascular bleeding, to occlude the blood supply to tumors, and toocclude vascular aneurysms, particularly intracranial aneurysms. Inrecent years, vascular embolization for the treatment of aneurysms hasreceived much attention. Several different treatment modalities havebeen shown in the prior art. One approach that has shown promise is theuse of thrombogenic microcoils. These microcoils may be made ofbiocompatible metal alloy(s) (typically a radio-opaque material such asplatinum or tungsten) or a suitable polymer. Examples of microcoils aredisclosed in the following patents: U.S. Pat. No. 4,994,069 to Ritchartet al.; U.S. Pat. No. 5,133,731 to Butler et al.; U.S. Pat. No.5,226,911 to Chee et al.; U.S. Pat. No. 5,312,415 to Palermo; U.S. Pat.No. 5,382,259 to Phelps et al.; U.S. Pat. No. 5,382,260 to Dormandy, Jr.et al.; U.S. Pat. No. 5,476,472 to Dormandy, Jr. et al.; U.S. Pat. No.5,578,074 to Mirigian; U.S. Pat. No. 5,582,619 to Ken; U.S. Pat. No.5,624,461 to Mariant; U.S. Pat. No. 5,645,558 to Horton; U.S. Pat. No.5,658,308 to Snyder; and U.S. Pat. No. 5,718,711 to Berenstein et al.;all of which are hereby incorporated by reference.

A specific type of microcoil that has achieved a measure of success isthe Guglielmi Detachable Coil (“GDC”), described in U.S. Pat. No.5,122,136 to Guglielmi et al. The GDC employs a platinum wire coil fixedto a stainless steel delivery wire by a solder connection. After thecoil is placed inside an aneurysm, an electrical current is applied tothe delivery wire, which electrolytically disintegrates the solderjunction, thereby detaching the coil from the delivery wire. Theapplication of current also creates a positive electrical charge on thecoil, which attracts negatively-charged blood cells, platelets, andfibrinogen, thereby increasing the thrombogenicity of the coil. Severalcoils of different diameters and lengths can be packed into an aneurysmuntil the aneurysm is completely filled. The coils thus create and holda thrombus within the aneurysm, inhibiting its displacement and itsfragmentation.

Alternative vaso-occlusive devices are exemplified in U.S. Pat. No.6,299,619 to Greene, Jr. et al.; U.S. Pat. No. 6,602,261 to Greene, Jr.et al.; U.S. Pat. No. 6,605,101 to Schafer et al.; U.S. Pat. No.7,029,486 to Schaefer et al.; U.S. Pat. No. 7,033,374 to Schaefer etal.; U.S. Pat. No. 7,331,974 to Schaefer et al.; and in co-pending U.S.patent application Ser. No. 10/631,981 to Martinez; U.S. patentapplication Ser. No. 11/398,081 to Schaefer et al.; and U.S. patentapplication Ser. No. 11/398,082 to Schaefer et al., all of which areassigned to the assignee of the subject invention and incorporatedherein by reference.

There is, however, an ongoing need to provide more advanced and improvedneuro-embolic microcoils that exhibit greater stability after deploymentin a target site; improved space seeking ability within the target site;wider application for treatment of target sites of varying sizes; andincreased efficacy for treating and occluding the target site.

OBJECTS AND SUMMARY OF THE INVENTION

The present invention provides a more advanced and improved occlusiondevice, for example an occlusion device in the form of a neuro-embolicmicrocoil, that exhibits greater stability after deployment in a targetsite; improved space seeking ability within the target site; widerapplication for treatment of target sites of varying sizes; andincreased efficacy for treating and occluding the target site. In oneembodiment, the occlusion device comprises a microcoil having a relaxedconfiguration comprising a plurality of open loop portions interposedbetween a plurality of closed loop portions.

In another embodiment, the occlusion device comprises a microcoil havinga relaxed configuration comprising a plurality of open loop portionsinterposed between a plurality of closed loop portions, each of theplurality of open looped portions formed substantially within adifferent plane.

In another embodiment, the present invention provides a method foroccluding a body cavity comprising passing a delivery system through avasculature until a distal end of the delivery system is positioned at atarget location; advancing a first portion of the occlusion device fromthe distal end of the delivery system into the target site, the firstportion forming a closed loop when the occlusion device is in a relaxedstate; advancing a second portion of the occlusion device from thedistal end of the delivery system into the target site, the secondportion forming at least one open loop when the occlusion device is in arelaxed state; advancing a third portion of the occlusion device fromthe distal end of the delivery system into the target site, the firstportion forming a closed loop when the occlusion device is in a relaxedstate; and releasing the occlusion device from the delivery system andwithdrawing the delivery system from the vasculature.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, features and advantages of which embodiments ofthe invention are capable of will be apparent and elucidated from thefollowing description of embodiments of the present invention, referencebeing made to the accompanying drawings, in which

FIG. 1 is a perspective view of a portion of a microcoil employed toform a device according to the present invention;

FIG. 2 is a perspective view of device according to one embodiment ofthe present invention.

FIG. 3 is a perspective view of a device on a mandrel employed tofabricate the device according to one embodiment of the presentinvention;

FIG. 4 is a perspective view of a device according to one embodiment ofthe present invention.

FIGS. 5A through 5C are perspective views of a device on a mandrelemployed to fabricate the device according to one embodiment of thepresent invention.

FIG. 6 is a perspective view of a device according to one embodiment ofthe present invention.

FIG. 7A is a perspective view of a device according to one embodiment ofthe present invention.

FIG. 7B is a perspective view of a mandrel employed to fabricate adevice according to one embodiment of the present invention.

FIG. 7C is a perspective view of a device on a mandrel according to oneembodiment of the present invention.

FIG. 8A is a perspective view of a device according to one embodiment ofthe present invention.

FIG. 8B is a perspective view of a mandrel employed to fabricate adevice according to one embodiment of the present invention.

FIG. 8C is a perspective view of a device on a mandrel according to oneembodiment of the present invention.

FIG. 9 is a perspective view of a device according to one embodiment ofthe present invention.

FIG. 10 is a perspective view of a device according to one embodiment ofthe present invention.

FIG. 11 is a table describing various configurations of a deviceaccording to one embodiment of the present invention.

FIG. 12 is a perspective view of a device according to one embodiment ofthe present invention.

DESCRIPTION OF EMBODIMENTS

Specific embodiments of the invention will now be described withreference to the accompanying drawings. This invention may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the invention to those skilled in the art. Theterminology used in the detailed description of the embodimentsillustrated in the accompanying drawings is not intended to be limitingof the invention. In the drawings, like numbers refer to like elements.

Devices or packing coils according to the present invention provideimproved stability after deployment in a target site; improved spaceseeking ability within the target site; wider application for treatmentof target sites of varying sizes; and increased efficacy for occlusionand treatment of the target site. Broadly speaking, these objectives areachieved by employing a microcoil having a relaxed, low-energy stateconfiguration incorporating both closed loop portions and open loopportions.

With reference to FIG. 1, devices or packing coils according to thepresent invention are formed of a suitable length of wire 12 formed intoa primary winding in the shape of a helical microcoil 14. Suitablematerials for the wire 12 include platinum, rhodium, palladium, rhenium,tungsten, gold, silver, tantalum, and various alloys of these metals.Various surgical grade stainless steels may also be used. Preferredmaterials include the platinum/tungsten alloy known as Platinum 479 (92%Pt, 8% W, available from Sigmund Cohn, of Mount Vernon, N.Y.) andtitanium/nickel alloys (such as the titanium/nickel alloy known as“Nitinol”). Another material that may be advantageous is a bimetallicwire comprising a highly elastic metal with a highly radiopaque metal.Such a bimetallic wire would also be resistant to permanent deformation.An example of such a bimetallic wire is a product comprising a Nitinolouter layer and an inner core of pure reference grade platinum,available from Sigmund Cohn, of Mount Vernon, N.Y., and Anomet Products,of Shrewsbury, Mass.

In embodiments useful for treating neurovascular malformations, the wire12 employed to form microcoil 14 has, for example, a diameter in therange of 0.001 to 0.005 inches. The microcoil 14 has a diameter that isin the range of about 0.008 to 0.016 inches. The axial length of themicrocoil 14 may be anywhere from about 2 to 100 cm. In embodimentsuseful for treating larger maliformations that may occur in theperipheral vasculature, the wire 12 may be larger, for example from0.005 to 0.015 inches. The microcoil 14 may have a diameter in the rangeof about 0.010 to 0.050 inches. The axial length of the microcoil may befrom 1 to 200 cm. Those skilled in the art will appreciate that the wiresize, coil diameter, and length are a matter of design selection and areusually scaled to the malformation intended to be treated.

The primary winding of the microcoil 14 is applied under tension. Theamount of tension and the pitch of the primary winding determine thestiffness of the microcoil 14. These parameters can be varied along thelength of the microcoil 14 to form a microcoil having different degreesof stiffness along its length, which may be advantageous in certainapplications.

The microcoil 14 is formed into a relaxed or minimum energy stateconfiguration by winding or otherwise manipulating the microcoil 14about a fixture or mandrel 20. Once associated with the mandrel 20, themicrocoil 14 and the mandrel 20 are subjected to a heat treatment, as iswell known in the art. For example, an annealing temperature of about500 degrees Celsius to about 1000 degrees Celsius is maintained forabout 30 to 90 minutes, the microcoil 14 and the mandrel 20 are thencooled to room temperature and ultrasonically cleaned. The resultantsecondary configuration is thereby made permanent and becomes therelaxed or minimum energy state configuration of the device 10.

With reference to FIG. 2, a device or packing coil 10 according to oneembodiment of the present invention employs a closed loop portion 16 andan open loop portion 18. The closed loop portions 16 form substantiallyclosed loops. The term “closed loop” refers to the feature in which aportion of the microcoil 14 approximately returns to or contacts anotherportion of the same microcoil 14. Such a return or contact may, forexample, appear as a stacking of two portions of the microcoil 14 on topof one another, as shown in FIGS. 7A, 8A, 9, and 10. The substantiallyclosed loops formed by the closed loop portion 16 may be formed in thegeneral shape of circles, ovals or other regular geometric or irregularshapes and need not be uniformly formed within the same device 10.

As shown in FIGS. 2-4, some or all of the closed loop portions 16 maydefine a plane. That is to say, the closed loop portions 16 may besubstantially flat and define an area or boundary through which a planecould be approximately positioned. It is further contemplated that someor all of the closed loop portions 16 may define one or more curves inthe X and the Y planes. Furthermore, some or all of the closed loopportions 16 have diameters of equal lengths. In one embodiment, at leastone of the diameters of the closed loop portions 16 is formed relativeto a dimension of a vascular site in which the device 10 is intended tobe placed. In certain embodiments of the present invention, the closedloop portions 16 have diameters of different lengths such as that shownin Fig, 10. For example, the diameter of the closed loop portions 16 maysequentially increase, decrease, alternate between increasing anddecreasing, or otherwise vary throughout the coil 10.

The closed loop portions 16 are, for example, formed by winding themicrocoil 14 around pins 22 that project outward from the mandrel 20 oneor more rotations. For example, the closed loop portions 16 may beformed by winding the microcoil 14 around the pin 22 in the range of 1to 4 rotations. The closed loop portions 16 may be wound about the pins22 in either a clockwise or a counter-clockwise direction. The directionof the windings may but need not be uniform throughout the device 10.The direction of the windings about the pins 22 of the present inventionmay be determined from the perspective of viewing down the length of thepin 22 with the free end of the pin 22 closest to the viewer. Where themicrocoil 14 is stacked upon itself, the portion of the winding furthestfrom the viewer, i.e. on the bottom of the stack, represents thebeginning of the winding and the portion closest to the viewerrepresents a subsequent or later portion of the winding. Statedalternatively, a winding or loop is formed from the bottom up relativeto the mandrel 20.

The open loop portions 18 of the device 10 are formed in the shape of aseries of open loops, curves, or waves spanning, for example as shown inFIGS. 2-4, between two closed loop portions 16. The term “open loop”refers to the feature in which a portion of the microcoil 14 folds ordoubles on to itself without contacting itself, thereby leave anopening. The individual open loops of the open loop portion 18 may, forexample, have a “C”, “U”, or “V” like form. It is noted that theindividual open loops of the open looped portions 18 may be formed bywinding the microcoil 14 around a portion of the pin 22 less than onefull rotation. For example, a single open loop portion 18 may employthree individual open loops each formed by winding the microcoil 14about a portion of a different pin 22 and each separated from oneanother by an inflection point. A single open looped portion 18 mayemploy between one and 10 individual open loops.

The form or shape of the individual open loops within a single open loopportion 18 may be the same or vary. The number and the form of theindividual open loops employed within different open loop portions 18may be the same or vary between different open loop portions 18 within asingle device 10. As shown in FIG. 12, the height 30 of individual openloops relative to one another, for example determined as the distancebetween sequentially formed curves of the individual open loops, may bethe same or vary within a single open loop portion 18 and may be thesame or vary between different open loop portions 18 within a singledevice 10. As also shown in FIG. 12, the width 32 of individual openloops relative to one another, for example determined as the distancebetween the inflection points of sequentially formed individual openloops, may be the same or vary within a single open loop portion 18 andmay be the same or vary between different open loop portions 18 within asingle device 10.

As shown in FIGS. 2-5C 7A, 7C, 8A, 8C, 9, and 10, the open loop portions18 may be formed substantially within a single plane, i.e. the open loopportions 18 may be substantially flat. Alternatively, the open loopportions 18 may be formed substantially within one or more curves in theX and Y planes.

In one embodiment of the present invention, the relaxed or minimumenergy state configuration of the device 10 may be formed on a mandrel20, for example, having a generally cube-like shape, as shown in FIGS.3, and 5A-5C. FIGS. 2 and 4 show one example of a device 10 formed onsuch a cube-like mandrel 20.

For the sake of clarity, the pins 22 indicated in FIG. 3 are shown asvoids rather than pins projecting out from the mandrel 20. Also for thesake of clarity, FIGS. 5A-5C depict the mandrel 20 and the device 10 insimplistic line drawings. As will be noted, the pins 22 are not shown inFIGS. 5A-5C. In order to better show the device 10, FIGS. 5A-5C eachshow the same device 10 on the same mandrel 20, however the mandrel isrotated 90 degrees in each subsequent figure. More particularly, FIG. 5Ashows a side A facing the viewer, and FIG. 5B, in which the mandrel 20has been rotated 90 degrees clockwise, shows the side A to the left,obscured from the viewer. Likewise, in FIG. 5C, side A is furtherrotated and facing away from the viewer.

As shown in FIGS. 5A-5C, the device 10 employs four closed loop portions16 a, 16 b, 16 c, and 16 d. The device is shown with two closed loopportions 16 on each side of the cube-like mandrel 20. The device furtheremploys six open loop portions 18 a, 18 b, 18 c, 18 d, 18 e, and 18 fspanning between certain pairs of the closed loop portions 16 a, 16 b,16 c, and 16 d. It will be noted that each of the closed loop portions16 are directly connected to three other closed loop portions 16 bythree different open loop portions 18.

It is further noted that the open loop portion 18 f is not shown in FIG.3 as the open loop portion 18 f spans between closed loop portions 16 cand 16 d on the side F of the mandrel 20 that is obscured from theviewer. The open loop portion 18 f is shown in FIGS. 4 and 5A-5C inwhich the mandrel 20 is not shown or shown in a transparent manner.

In certain embodiments of the present invention, the device 10 is formedon a mandrel 20 having a shape other than a three-dimensional cube-likeshape. For example, the mandrel 20 may be formed in a two or threedimensional rectangular, triangular, tetrahedral, circular, oval orother regular geometric or irregular shape. It is contemplated that anynumber of the closed loop portions 16 and open loop portions 18 can beemployed in a single device 10 of the present invention.

In certain other embodiments of the present invention, the closed loopportions 16 need not form intersection-like points for a plurality ofthe open loop portions 18 as shown in FIGS. 2-5C. Rather the closed loopportions 16 may be formed in a sequential manner connected to oneanother by the open loop portions 18, as shown in FIG. 6-8C. Forexample, as shown in FIG. 6, a device 90 employs only two closed loopportions 16 connected to one another by one open loop portion 18.

In another example, as shown in FIGS. 7A and 8A, a device 110 is shownfrom different perspectives in a relaxed, low-energy state as the device110 would appear on the mandrel or fixture upon which the device 110 isformed. FIGS. 7B and 8B show a mandrel 120 used to make the device 110from the same perspective, respectively. FIGS. 7C and 8C show the device110 on the mandrel 120 from the same perspectives, respectively.However, for the sake of clarity, the pins 22 of the mandrel 120 havebeen omitted. The device 110 employs the closed loop portion 16 a thatis connected to the closed loop portion 16 b by the open loop portion 18a. The closed loop portion 16 b is, in turn, connected to the closedloop portion 16 c by the open loop portion 18 b. This configuration isrepeated along the length of the device 110. Stated alternatively, eachclosed loop portion 16 is connected to the next sequentially formedclosed loop portion 16 by one open loop portion 18.

As shown in FIG. 7B and 8B, the device 110 is formed on the fixture ormandrel 120. The mandrel 120 employs pins 22 as described aboveregarding the device 10. The mandrel further employs one or more pins124 that attach subassemblies 122 to one another. The pin 124 attaches asubassembly 122 a to a subassembly 122 b. In order to more easily relateFIGS. 7A-8C to one another, it is noted that the closed loop portion 16d is formed on the pin 124. The subassemblies 122 a and 122 b are formedin a generally cube-like form. However, for the sake of clarity, it isnoted that the corners of the subassemblies 122 a and 122 b that do notemploy the pin 22 or 124 have been omitted or removed from thesubassemblies 122 a and 122 b.

It is noted that while the device 110 is shown as employing seven of theclosed loop portions 16 and six of the open loop portions 18, the device110 may employ as few as three of the closed loop portions 16 and two ofthe open loop portions 18. The closed loop portions 16 may havediameters ranging from approximately 2 to 20 millimeters, or 3 to 15millimeters. The closed loop portions 16 of the device 110 may be of auniform diameter or may vary in diameter. The number and form of theopen loops employed within different open loop portions 18 may be thesame or vary between different open loop portions 18 within a singledevice 110. For example the number of curves in a single open loopportion 18 may vary within the range of 2 to 6. The arc of the curvesforming the individual open loops of the open loop portions 18 may alsovary within a single open loop portion 18 or within a device 110.

In one embodiment of the present invention, the device 110 is formed bywinding the microcoil 14 in the same direction for all the pins 22 onthe subassembly 122 a and in an opposite direction for all the pins 22on the subassembly 122 b.

In another embodiment of the present invention, the devices 210 and 310,shown in FIGS. 9 and 10 respectively, are formed on the above describedmandrel 120 having the subassemblies 122 a and 122 b. However, as bestseen through a comparison of FIG. 7A and FIGS. 9 and 10, the closed loopportion 16 d of the devices 210 and 310 are formed by winding themicrocoil 14 fewer rotations than the closed loop 16 d of device 110.More particularly, as shown in FIG. 9, the closed loop portion 16 d ofthe device 210 is formed by winding the microcoil 14, for example,approximately 1 to 1.25 rotations. As shown in FIG. 10, the portion ofthe microcoil 14 of the device 310 that is wound around what would bepin 124 of the mandrel 20 shown in FIG. 7B, is wound approximately lessthan one rotation. For the sake of clarity, this portion of themicrocoil 14 is referenced as portion 16 d′ in FIG. 10. It is noted thatthe different degrees of rotations employed to form the closed loop 16 dof device 210 and the portion 16 d′ of device 310 may be achieved byrotation of the subassembly 122 b relative to the subassembly 122 a.Accordingly, it is noted that while the number of rotations employed toform closed loop portion 16 d and the portion 16 d′ may vary, therelative structural orientation of sequentially formed closed loopportions 16 a-16 d, 16 a-16 c to one another and the relative structuralorientation of sequentially formed closed loop portions 16 d-16 g, 16e-16 g to one another remains unchanged.

Described in Table 1 shown in FIG. 11 are various exemplaryconfigurations of the device 310 according to the present invention. Ascan be seen, the device 310 may be formed of a plurality of the closedloop portions 16 having, for example, diameters ranging from 3 to 15millimeters. The closed loop portions 18 may, for example, be formed bywinding the microcoil 14 around the pin 22 from one to 2.25 rotations.The device 310 may, for example, be formed of a total of three to sevenclosed loop portions 16 and two to six open loop portions 18.

In another embodiment of the present invention, as shown in FIG. 12, thedevice 10, 110, 210, 310, in the relaxed or minimum energy stateconfiguration, employs a series of closed loop portions 18 and open loopportions 16 that sequentially increase or decrease in size. For example,each subsequent closed loop portion 16 has a smaller diameter than thepreceding closed loop portion 16 and each subsequent open loop portion18 has a smaller height 30 and/or width 32 than the preceding open loopportion 18.

In certain embodiments of the present invention, the devices 110, 210,and 310 are formed on a mandrel 120 having a shape other than that shownin FIG. 7B and 8B. For example, the mandrel 120 may be formed of asingle or multiple two or three dimensional rectangular, triangular,tetrahedral, circular, oval or other regular geometric or irregularshape. It is contemplated that any number of the closed loop portions 16and open loop portions 18 can be employed in a single device 110, 210,and 310 of the present invention.

In certain other embodiments of the present invention, the closed loopportions 16 may be formed proximate one another, i.e. the open loopportion 18 need not span between two of the closed loop portions 16.

In certain embodiments of the present invention, the normal planesdefined by sequentially formed closed loop portions 16 and open loopportions 18 are neither coincident nor parallel to one another. Incertain embodiments of the present invention, the normal planes definedby sequentially formed closed loop portions 16 intersect to form a 90degree angle or other non-zero and non-180 degree angles. In certainembodiments of the present invention, sequentially formed open loopportions and closed loop portions form an angle greater than 90 degreesand less than 180 degrees. In certain embodiments of the presentinvention, the normal planes defined by certain, but not necessarilyall, sequentially formed open loop portions 18 intersect to form a 90degree angle or other non-zero and non-180 degree angle.

It is believed that the open loop portions 18 of the device 10 allow forcertain improvements over known occlusion devices. For example, therelatively planar sections of the open loop portions 18 provide enhancedcolumn strength to facilitate improved space seeking properties of thedevice 10. Additionally, the overall length of the open loop portions 18allow for effective treatment of a range of target sites with a singledevice 10, 110. For example, a six millimeter device 10, 110, 210, 310,may be able to treat 6 to 10 millimeter aneurysms.

With respect to the closed loop portions 16 of the device 10, 110, 210,310, the closed loop portions 16 provide intersecting point and ends tothe open loop portions 18 that assist in preventing the formation ofsudden or sharp angles within the device that may cause undesiredpressure points within the target site.

Accordingly, the open loop portions 18 and the closed loop portions 16function together to provide the device or packing coil 10, 110, 210,310, according to the present invention with improved stability afterdeployment in a target site; improved space seeking ability within thetarget site; wider application for treatment of target sites of varyingsizes; and increased efficacy for occlusion and treatment of the targetsite.

In alternative embodiments of devices according to the presentinvention, a device employs a combination of any of the above disclosedfeatures.

In order to deliver the device of the present invention to a target,such as an aneurysm, the proximal end of the microcoil 14 of device isattached to the distal end of an elongate delivery device, such as aguidewire or microcatheter (not shown). The attachment may be by any ofa number of ways known in the art, as exemplified by the following U.S.patents, the disclosures of which are expressly incorporated herein byreference: U.S. Pat. Nos. 5,108,407 to Geremia et al.; 5,122,136 toGuglielmi et al.; 5,234,437 to Sepetka; 5,261,916 to Engelson; 5,304,195to Twyford, Jr. et al.; 5,312,415 to Palermo; 5,423,829 to Pham et al.;5,522,836 to Palermo; 5,645,564 to Northrup et al.; 5,725,546 to Samson;5,800,453 to Gia; 5,814,062 to Sepetka et al.; 5,911,737 to Lee et al.;5,989,242 to Saadat et al.; 6,022,369 to Jacobsen et al.; 6,063,100 toDiaz et al.; 6,068,644 to Lulo et al.; and 6,102,933 to Lee et al.

Delivery of the packing coil of the present invention may be achieved byemploying features of the attachment and delivery devices described inthe Assignee's of the present subject matter U.S. ProvisionalApplication Ser. No. 60/604,671, filed Aug. 25, 2004, entitled ThermalDetachment System For Implantable Devices; U.S. Provisional ApplicationSer. No. 60/685,342 filed May 27, 2005, entitled Thermal DetachmentSystem For Implantable Devices; U.S. patent application Ser. No.11/212,830 filed Aug. 25, 2005, entitled Thermal Detachment System ForImplantable Devices; U.S. Provisional Application Ser. No. 60/952,520filed Jul. 27, 2007, entitled Detachable Coil Incorporating StretchResistance; U.S. Provisional Application Ser. No. 61/016,154 filed Dec.21, 2007, entitled System and Method For Locating Detachment Zone Of ADetachable Implant; and U.S. Provisional Application Ser. No. 61/324,246filed Apr. 14, 2010, entitled Implant Delivery Device which are eachherein incorporated in their entirety by reference.

A method for treating a vascular target with the device may includevisualizing the target vascular site by means well-known in the art. Thetarget vascular site may be, for example, an aneurysm branching off aparent artery. Such an aneurysm may have a dome connected to the branchartery by a neck. A catheter is passed intravascularly until it entersthe dome of the aneurysm via the neck. The device is passed through thecatheter with the assistance of the guidewire or microcatheter until adistal end of the device 10 enters the dome of the aneurysm.

As the device enters the aneurysm, it attempts to assume its relaxed,low-energy configuration. Because the microcoil, in its relaxedconfiguration, is larger than the aneurysm, it is constrained into adeployed configuration in which it tends to line the periphery of theaneurysm. In this deployed configuration, the microcoil is in an energystate that is substantially higher than its relaxed, low-energy state.Thus, when the device is deployed inside a vascular site such as ananeurysm, the confinement of the device within the site causes thedevice to assume a three-dimensional configuration that has a higherenergy state than the relaxed energy state. Because the relaxed energystate of the device is larger (in at least one dimension) than the spacein which it is deployed, the deployed device is constrained by itsintimate contact with the walls of the aneurysm from returning to itsminimum energy state configuration. Therefore, the device engages thesurrounding aneurysm wall surface, thereby minimizing shifting ortumbling due to blood flow dynamics. Furthermore, the relaxed energystate secondary configuration (to which the device attempts to revert)is not one that is conducive to “coin stacking”, thereby minimizing thedegree of compaction that is experienced.

Although the invention has been described in terms of particularembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit of or exceeding the scope of theclaimed invention. Accordingly, it is to be understood that the drawingsand descriptions herein are proffered by way of example to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

What is claimed is:
 1. An occlusion device comprising: a microcoilhaving a relaxed configuration comprising a plurality of open loopportions, each open loop portion of the plurality of open loop portionsinterposed between two different closed loop portions; each open loopportion of the plurality of open loop portions formed of a plurality ofopen loops formed substantially within a single plane.
 2. The occlusiondevice of claim 1 wherein each of the closed loop portions is positionedsubstantially within a different plane relative to one another.
 3. Theocclusion device of claim 1 wherein at least two of the closed loopportions are formed by winding the microcoil in opposite directions. 4.The occlusion device of claim 1 wherein each of the closed loop portionsis formed by winding the microcoil from 1 to 4 rotations.
 5. Theocclusion device of claim 1 wherein the microcoil in the relaxedconfiguration comprises from 2 to 7 closed loop portions.
 6. Theocclusion device of claim 1 wherein each of the plurality of open loopportions is positioned substantially within a different plane relativeto one another.
 7. The occlusion device of claim 1 wherein the microcoilin the relaxed configuration comprises from 2 to 6 open loop portions.8. The occlusion device of claim 1 wherein an open loop portion of theplurality of open loop portions comprises from 2 to 10 individual openloops.
 9. The occlusion device of claim 1 wherein sequentially formedopen loop portions and closed loop portions define differentnon-parallel planes.
 10. An occlusion device comprising: a microcoilhaving a relaxed configuration comprising a plurality of open loopportions, each open loop portion of the plurality of open loop portionsinterposed between two different closed loop portions; each open loopportion of the plurality of open loop portions formed substantiallywithin a different plane relative to one another; each open loop portionof the plurality of open loop portions formed of a plurality of openloops formed substantially within a single plane.
 11. The occlusiondevice of claim 10 wherein sequentially formed open loop portions andclosed loop portions form an angle greater than 90 degrees and less than180 degrees.
 12. The occlusion device of claim 10 wherein at least twoof the closed loop portions are formed by winding the microcoil inopposite directions.
 13. The occlusion device of claim 10 wherein eachof the closed loop portions is positioned substantially within adifferent plane relative to one another.
 14. The occlusion device ofclaim 10 wherein sequentially formed open loop portions and closed loopportions define different non-parallel planes.